Simulation And Analysis Of Hydrodynamic Field In Kuqa Depression

Hydrodynamic field makes an important effect on hydrocarbon migration and accumulation.It is of great significance for petroleum exploration and development to make paleo fluid dynamic field reappear correctly.Based on the observed data of the existing constraints,a new model is built by using the method of numerical simulation and basin modeling software.Making use of the model let burial history,temperature field and the evolution of paleo three-dimensional fluid dynamic field reappear in Kuqa sag,in order to analyze the characteristics of fluid dynamic field and its influence on hydrocarbon migration and accumulation with three-dimensional perspective in Kuqa sag.In my research,first of all,3D geological framework and 3D fault plane were established based on log layering,seismic profile interpretation and application of Petrel software.Secondly,different lithology was defined through the application of well logging,formation testing and rock physics data in the study area.According to the results of sedimentary facies and stratification,the plane distribution and vertical distribution of lithology in the study area are also defined.At last,based on the simulation results of single well,the results of previous studies and the related software,the three boundary conditions,such as the paleo water depth,the evolution of terrestrial heat flow value and the interface temperature of the paleo sedimentary.The development of faults and the extensive gypsum salt beds are the characteristics of the study area.On the basis of the three-dimensional fault plane,the SGR diagram of the fault is calculated according to the logging data to judge the fault sealing.Based on the previous research results,the formation of fault and the main active period are defined.Based on the seismic interpretation section,the plastic model is used to define the gypsum salt layer.Based on the definition of the above parameters,the simulation of burial history,thermal history,fluid dynamic field and hydrocarbon migration and accumulation in the study area is carried out.Research shows that the subsidence speed of Kuqa sag strata is slower in Mesozoic.Since the Cenozoic,the subsidence velocity is accelerated by the Himalaya movement,in the late kuqa formation sedimentary period up to maximum buried depth.The evolution of the formation temperature and the hydrodynamic field are controlled by the tectonic movement.The temperature and fluid dynamics in the north of Kelasu region have experienced a rapid increase and decrease since 5Ma.The maximum paleo temperature has reached the threshold of oil generation.Totally,the hydrodynamic distribution of Baicheng sag is reduced gradually to the surrounding tectonic units.However,under the influence of tectonic compression,the hydrodynamic force tends to decrease from north to south in the strong thrust belt of Kelasu.The overpressure in the Jurassic and Cretaceous is generally developed in the Baicheng sag.The oil and gas generated from the Jurassic source rocks are transported to the Cretaceous reservoirs with overpressure as the driving force.The pressure difference between the source and reservoir in the Baicheng sag is the largest at the end of the sedimentation of Kuqa strata,which is beneficial for the vertical hydrocarbon expulsion of the source rock.The momentum and potential gradient of different periods show that the strong and consistent hydrodynamic field which has been the guarantee of the formation of the gas field(such as the Kra 2 gas field)in the strong squeezing background since 5 Ma.